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Brewing Water Simplified
By Dr. Pivo
The subject of water used for brewing purposes is extremely complex, and can both baffle and discourage potential brewers with a poor background in chemistry. The following comments are meant as a guide to people with a genuine interest in whole grain brewing who don't know a pKa from a poke in the arse.
The Process
The basic consideration in brewing (leaving yeast nutrients aside) is the pH (or acidity) of the mash. I am assuming here that the reader is familiar with the two diastatic enzymes in malt, and the resultant products : easily fermentable maltose, and that collection of less to non-fermentable complex sugars we call dextrins. When we mash in grains we form a "buffer". That is simply a liquid with a very stable pH. If you do things (add things) to that liquid it is very reticent to change pH. If you change either the water you started with (the naturally dissolved salts that it contains) or the type of grain you mash in, you will likely get another pH, and that one just as stable as your first. The pH of your mash will by and large determine how much of your grains starch will turn to maltose, and how much will be dextrins. There are other tricks, such as temperature adjustment, or degree of dilution which can influence that proportion, but my experience has been, that they are quite marginal effects compared to the pH you get from your initial mixture. In short, your water source and choice of grains will determine the beer.Historically Good Beers
If we take all but the most extreme of the classical beers, we can say that maltose comprises about 75-80% of the dissolved sugars after the mash. You will get that proportion if your mash pH is in the low 5's. You can hardly avoid it if your mash pH ends up there, and I doubt if you'll be able to attain it if it isn't. That means that all the classic beers have had that mash pH as well...imagine that-there is a unifying concept! I firmly disbelieve that these great beers were created because someone found a "great" brewing water, but rather, one simply found a consistent water source, after which, whether through trial and error, or accidentally (probably), there evolved a grain combination than when finished, fermented to about 75-80 percent of the original sugars having been converted to alcohol.
Water Manipulation
There are a great many both micro breweries and home brewers who use, for example "burtonizing salts", and I have tasted at each some very nice beers, that were not much like the ales of Burton-on-Trent. Now there are two important points here... they were not like the ales of Burton-on Trent, and they were very nice beers.
Beer is an incredibly complex collection of taste sensations both in itself, and in its natural state, because of its dynamic nature. Anyone who has put a keg of real beer in the trunk of there car and transported it a few kilometres, only to find subtle taste changes taking place already is acutely
Another approach, is rather than trying to recreate a classic, create your own "classic"!
Creating a Classic!
If you are going to create your own beer you are going to need some understanding of the water you have access to. You may have a community supply and can request information, or have an analysis done to see which beer styles are most likely to be compatible with your water (tedious, expensive), or just experiment (fun!fun!fun!)
The chances are, that if your water is palatable, some sort of beer will do just nicely. So the question is, which grains will bring me to an acceptable pH? I would suggest trying to get a hold of all of the major sorts of grains available. A pale malt, a Pilsener, a Bayer, a Munchner, a Vienna, and some colour malts (crystal ,chocolate, black). Of your basic malts, mash in a handful in a little pot on the stove, with about an equal amount of water. Hold the mixture at about 150F (67C) for about 15 minutes and measure the pH. The temperature is not terribly critical here, we're not trying to preserve enzymatic action here, just see where the buffer is going to end up. If you don't have access to a pH electrode, for these purposes, Litmus paper will do just as well. You can purchase at any well sorted chemical supply house, a box of little strips of paper that change colour at .3 pH intervals. Just make sure that it covers the range between 5 and 6. There are a couple of different indicator systems (different colours), available, but I find the ones going from yellow to a bluish green easiest to read, but that could just be my eyes. I can't give a current price on these as I haven't purchased a new set in well over 10 years, and even a fairly dedicated fanatic should find that one box should last a lifetime of brewing ( once you have sussed out most of your grain permutations you will not have much frequent need of these). Once you have found out where your pH ends up with your basic grains, you might try mixing them, or adding colour malts. You will find that the relationship is not necessarily linear. That is, mixing equal amounts of two different malts will not give you a pH half way in between. This is partly due to the pH scale itself (logarithmic, not linear) and partly to the complex nature of buffer systems. You'll just have to fiddle around to find the truth here. I would say anything that gives you a pH under 6 is at least worth taking at shot at brewing. In the high 5's you would get a high proportion of dextrins, but that is not necessarily a disadvantage. Dextrins are not perceived as particularly sweet, and a certain extra portion can easily be balanced in your hopping. Commercial breweries live by the constraint that they must produce near maximum alcohol per invested amount of raw material, or produce a taste that matches an established market share, but you don't-we're after you're taste here.
If all this sounds a bit complicated. You might just try brewing. You'll invest a lot more grain in each "experiment", but the difference between your gravity drop and your final gravity will approximately tell you your maltose/dextrin proportion and conversely your mash pH, and your tongue will tell you if you like it.
Conclusion
We are living in wonderful times for the home brewer. We have at our fingertips the choicest raw materials available to the "master brewers". Feel free to " mix and match" premash and mash temperatures, grains, hops, yeast and fermentation temperatures from wide ranging styles of beer production. Most of these were established when the local brewer had no choice, but you do! If you are going to create jour own "classic", you might start by seeing which sorts of grains your water is inviting you to use.